Fill in the blank to make the following statement true:
$\sqrt[11]{1} = \ldots$

$\sqrt{10} \times \sqrt{15}$ is equal to

Prove that,$\frac{1}{1+\sqrt{2}}+\frac{1}{\sqrt{2}+\sqrt{3}}+\frac{1}{\sqrt{3}+\sqrt{4}}=1$.

Find the values of $a$ and $b$ in each of the following:
$\frac{7+\sqrt{5}}{7-\sqrt{5}}-\frac{7-\sqrt{5}}{7+\sqrt{5}}=a+\frac{7}{11} \sqrt{5} b$

Classify the following numbers as rational or irrational with justification:
$(i)$ $\sqrt{\frac{9}{27}}$
$(ii)$ $\frac{\sqrt{28}}{\sqrt{343}}$

Visualise $2.365$ on the number line,using successive magnification.